| 摘要 |
An apparatus and method for determining the apparent intima-media thickness (IMT) of arteries through acquisition and analysis of ultrasound images comprising an array of pixel intensities. An acquired image may be referenced, determining threshold values relating to the intensity of pixels forming images of portions of an artery wall, particularly the lumen, media, and adventitia. A datum, or datums, may be established across multiple columns of pixels bounding the portion of the image containing either the lumen/intima boundary, the media/adventitia boundary, or both. The datums may be approximate the shape of one more of the lumen, intima, media, and adventitia. Within a bounded portion of the image, a method may search for intensity gradients having characteristics indicating the gradients represent probable locations of the lumen/intima and media/adventitia boundaries. A valid gradient may be identified by its proximity to a characteristic point on a graph of pixel intensities or to a datum line, by an intensity above or below a threshold, or both. An IMT measurement is calculated based on the location of the lumen/intima and media/adventitia boundaries. An IMT measurement may be adjusted for sloping or tapering of an artery wall. Taper adjustment may be accomplished by normalizing an IMT measurement based on a compiled database of IMT measurements relating the amount of taper with respect to location to characteristic IMT values.
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